Asset managers and securities analysts are watching for major securities firms to say they will adjust their systems to accommodate the new funds’ unique trading mechanism. NextShares investors will place orders during the trading day to be executed at an increment above or below the daily net asset value, or NAV, to be determined at the end of the day.

Folio Investing permits individual investors to put together portfolios of stocks, ETFs and mutual funds or to choose from ready-made portfolios. They can buy or sell an entire “folio” in one online click. Folio Institutional offers brokerage and custodial services for financial advisers and institutions. Foliofn works with about 500 advisory firms and declined to disclose the dollars invested in folios.

“We think there are some significant advantages to the NextShares structure,” said Steven Wallman, chief executive and founder of Foliofn and a former commissioner with the Securities and Exchange Commission.

The funds will offer the cost savings and tax advantages of an ETF-type structure in the context of actively managed funds, he said.

NextShares won’t disclose their holdings daily, as almost all ETFs do. That makes the structure attractive to some asset-management companies that are concerned about daily disclosure hobbling their trading ability.

Folio is hopeful that the funds will be offered by year-end, but Mr. Wallman said Eaton Vance is still awaiting some approvals from regulators.